Compressed gas operated circuit breaker



April 8, 1952 H. THOMMEN ET AL COMPRESSED GAS OPERATED CIRCUIT BREAKER Filed July 25, 1949 INVENTOR ATTORNEY Patented Apr. 8, 1952 COMPRESSED GAS OPERATED CIRCUIT BREAKER llan's lhommen and Arnold Amstutz, Baden, Switzerland, "assignors to Aktiengesellschaft Brown, Boveri '& Cie, Baden, Switzerland, a

joint-stock company Application July 25, 1949, "Serial no. 106,686 In Switzerland July 31-, .1948

The present invention relatesto circuit breakers of the gas blast type in which the breaker contacts, normally spring loaded into engaging relation in a switch chamber, are separated upon an application of pressure gas to the contacts, and remain open so long as the gas pressure is maintained in the chamber. Closure of the contacts is. effected "by releasing "the gas pressure in the chamber thuspermitting the counter forced the contact loading device to move the contacts to closed position. 1

With switches of the foregoing type, it is most desirable that the contact 'reclosure action take place as rapidly as possiblefand also while gas pressure is still present in'thfesWitch chamber *to prevent formation of longgswitching-in arcs. Moreover, care must be taken vtl'lat the contact pressure is great "enough to prevent the inherent electrodynamic forces irom separating the contacts and also to prevent mechanical rebounding of the contacts. These switching problems are most acute when the breaker is to be switched in without disturbance in cases involving heavy upon an opening operation of the "circuit breaker contacts.

The foregoing and other objects and advantages inherent in the invention will become "more apparent from the following detailed description of a typical embodiment thereqiwhen considered with the accompanying drawing which is a vertical view of the improved Iswitch arrangement with some components shown in central -section and others in elevation. y

Referring now to the the switch is seen to be comprised of a hollow insulator column In upstanding upon a valve body I I that is united with a tank I2 containing a compressed gas such as air which is used for actuating the switch contacts. The valvefbody "Ii includes two valve plates I3, I 4 cooperative with opposite ends of the valve cylinder I5 and interconnected by rod I6 for operation simultaneously in such 'man- 2 nor that when valve plate I3 is seated upon the cylinder end I5a, valve plate I4 is removed from its seat on the cylinder end I5b and vice versa. The cylinder I5 contains an opening I50 leading therefrom into the lower end of the insulator column Ill and a vent l'5d from cylinder end I5a to atmosphere. Thus when the valve plates I3, l4 occupy the positions shown in the drawing, the interior of the column Ill is placed in communication with the atmosphere through openings I50 and lid; similarly when the valve plates I3,

14 are shifted to the positions shown in broken lines, vent I5d is cut off by closure of valve cylinder end i511 and compressed air is admitted "from tank 'l'2into the column 40.

At an intermediate oint along the column In an annular plate i I of conductive material is in serted. This plate includes a terminal 18 to which one side L of the line is connected, and a spider 19 at the center or hub portion of which is supported a stationary cylindrical contact 20. Cooperative with this contact is a movable tubular contact 2|. The lower open end of contact 2| seats upon the end of contact 20, the upper end is secured to a valve plate 22 having a peripheral flange 22aand ports 23 are provided in the tubular wall to .permit discharge of the gases formed upon separation of the contacts.

Upstanding upon the insulator column I0 and of about the same internal diameter is another tubular column 24 of conductive material that carries a transversely arranged conductive plate '25 inserted between the ends thereof. Plate 25 includes one or more longitudinal gas passageways 26 therethrough, one or more gas ports 21 leading from the lower face of the plate to atmosphere, and an axial opening 28 that serves as a sleeve for guiding a conductive piston rod 29. The lower end of rod 29 is secured to valve plate 22 and a compression spring 30 carried between the lower face of plate 25 and valve plate 22 is preferably included to urge the interconnected components, i. e. piston rod' 29, valve plate 22 and tubular contact 2I downwardly so that contacts '20, 2| are normally loaded by the spring 30 into engagement. n

A piston 32 also of conductive material carried at the top of rod 29 works in a conductive cylinder "33 that is enclosed by a housing 34 also of conductive material. The upper end wall of cylinder 33 is provided with a very large opening 35 and a port 36 is provided in the side wall of the cylinder in order to'permit compressed gas to flow from the switch chamber 31 into a pressure storage, auxiliary chamber 38 after the piston 32 has moved to the position shown in broken lines.

Upstanding upon housing 34 is a second terminal 39 to which line L1, is connected and since the components associated with the tubular contact 2| are all conductive, a low resistance path for current flow is thus provided from line L,

through to the movable contact 2| of the switch.

As stated at the outset of the application, the object of the present invention is to provide a more rapid and positive reclosing action of the switch contacts. The construction described assures the desired result and operates in the following manner:

To effect an opening of the switch contacts 20, 2 I, valve control rod I6 is shifted by suitable control means (not illustrated) to the right from the position shown in the drawing thus closing end |a of valve cylinder I5 and opencylinder end l5b. Compressed air now flows from tank I2 through valve into the main switch chamber 31 causing contact 2| to move upward and away from contact 20 thus breaking the connection between lines L and L1. The are formed upon separation of the contacts is bathed on all sides by the compressed gas flowing upward around and through the movable contact 2| and ultimately extinguished, the arc discharge gases flowing out through exhaust port 21 to atmosphere. Valve plate 22 and piston 32 rise simultaneously with the movable contact 2| ultimately reaching the positions shown in broken lines at which time exhaust port 21 is closed by valve plate 22 thus shutting ofi the main switch chamber 31 from the surrounding air and opening port 36 in cylinder 33 to place the main switch chamber 31 in communication with the auxiliary chamber 38. The latter now fills with pressure gas from the main switch chamber flowing upwardly through the passageway 26 and the contacts 20, 2| will remain in the separated state being well insulated from one another by the compressed gas that fills chamber 31.

When it is desired to close the switch contacts, valve control rod I6 is shifted back to the position shown in full lines thus cutting off the interior of the insulator and conductive columns H], 24 from the compressed air tank l2 and simultaneously venting the columns to atmosphere through opening I511. The air under pressure in columns is now discharged rapidly through opening l5d. The air under pressure in the columns is now discharged rapidly through opening |5d thus dropping rapidly the pressure on the lower side of piston 32 which is then moved rapidly downward forthwith by the gas under pressure stand in the auxiliary chamber 38, and which pressure is applied to the upper side of piston 32 through the top opening 35 in cylinder ,33. Piston 32 and therefore the movable contact member 2| are propelled downwardly withgreat force thus effecting a rapid and positive reclosure of contacts 20, 2| and with such contact pressure that rebounding of the movable contact 2| is made impossible. Spring 30 also exerts a reclosing force on the movable contact 2| but as the spring force constitutes but a .very small fraction of the total reclosingv force, Iit can be disregarded. In fact, it is possible to eliminate the spring altogether so that the switching 'operations are carried out exclusively by pneumatic action.

An inherent and important advantage of the 4 sired pneumatic action is always attained irrespective of the magnitude of the air pressure in tank I2. The control operates equally as well on either high or low pressures and is obviously self compensating for difier'ent air pressures since is typical only and hence may be modified by others without however departing from the spirit and scope of the invention as defined in the appended claims.

We claim? 1. A compressed gas circuit breaker comprising, a switch contact chamber, a pair of normally closed switch contacts in said chamber, said contacts being separated by compressed gas upon admission thereof to said chamber and maintained in said separated state by the gas pressure in said chamber, a source of compressed gas, valve means for establishing communication between said chamber and gas source, valve means controlling relief of the gas pressure from said chamber, a pressure storage auxiliary chamber communicable only with said switch contact chamber, a piston cooperative with a movable one of said contacts for efiectingreclosure thereof, opposite sides of said piston being continuously exposed respectively to the gas pressures in said switch contact and auxiliary chambers, andmeans for charging'said auxiliary chamber with compressed gas from said switch contact chamber whereby to effect movement of said piston in the contact reclosing direction .by the ber, a piston cooperative with a movable one of said contacts for effecting reclosure thereof, opposite sides of said piston being continuously exposed respectively to the gas pressures in said ,switch'contact and auxiliary chambers, and valve means interconnecting said chambers controlled by said piston for charging said auxiliary chamber with compressed gas from said switch contact .chamber whereby to effect movement of said piston in the contact reclosing direction by the gas pressure in said auxiliary chamber forthwith upon relief of the gas pressure from said switch contact chamber.

3. A compressed gas circuit breaker comprising, ;a,. switch contact chamber, a pair of normallylclosed switch contacts in said chamber, said contacts beingseparated by compressed gas upon admission thereof to said chamber and maintained in said separated state by the gas pressure in said chamber, a source of compressed gas, valve meansfor establishing communication between said chamber and gas source, valve means controlling relief of gas pressure from said chamber, a pressure storage auxiliary chamber,

a piston cooperable with one of said contacts for moving the same in the direction of the other contact to effect reclosure of said contacts, opposite sides of said piston being continuously exposed respectively to the gas pressures in said switch contact and auxiliary chambers, and a passageway between said chambers controlled by said piston for charging said auxiliary chamber with compressed gas from said switch contact chamber whereby to eiiect movement of said piston in the contact reclosing direction by the gas pressure in said auxiliary chamber forthwith upon relief of the gas pressure from said switch contact chamber.

4. A compressed gas circuit breaker as defined in claim 3 wherein said piston is secured to one of said contacts.

5. A compressed. gas circuit breaker as defined in claim 3 wherein said auxiliary chamber includes an open cylinder within which said piston slides, and the said passageway between said chambers is constituted by an opening through the cylinder wall.

6. A compressed. gas circuit breaker comprising, a switch contact chamber, a pair of normally closed switch contacts in said chamber, said contacts being separated by compressed upon admission thereof to said chamber and maintained in said separated state by the gas pressure in said chamber, a source of compressed as, valve means for establishing communication between said chamber and gas source, valve means controlling relief of gas pressure from aid chamber, a pressure storage auxiliary chamber, a piston secured. to one of said contacts for moving the same in the direction of the other contact to effect reclosure of said contacts-01% posite sides of said piston being continuously exposed respectively to the gas pressures in said switch contact and auxiliary chambers, spring means cooperable with the contact to which said piston is secured for loading said contact in the contact reolosing direction, and a passageway between said chambers controlled by said piston opened upon separation of said contacts for charging said auxiliary chamber with compressed gas from said switch contact chamber whereby to eiiect movement of said piston in the contact rcclosing direction by the gas pressure in said auxiliary chamber and said spring forthwith upon relief of the gas pressure from said switch contact chamber and in a counter direction by the compressed gas when admitted to said swi ch contact chamber.

7. A compressed gas circuit breaker as defined in claim 6 and which further includes a port in said switch contact chamber for venting are discharge gases due to contact separation, and valve means controlled by the movable one of said con tacts for closing said port subsequent to separation of the contacts.

' HANS THOMMEN.

ARNOLD AMSTUTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

